RESUMO
Optic neuropathies are leading causes of irreversible visual impairment and blindness, currently affecting more than 100 million people worldwide. Glaucoma is a group of optic neuropathies attributed to progressive degeneration of retinal ganglion cells (RGCs). We have previously demonstrated an increase in survival of RGCs by the activation of macrophages, whereas the inhibition of macrophages was involved in the alleviation on endotoxin-induced inflammation by antagonist of growth hormone-releasing hormone (GHRH). Herein, we hypothesized that GHRH receptor (GHRH-R) signaling could be involved in the survival of RGCs mediated by inflammation. We found the expression of GHRH-R in RGCs of adult rat retina. After optic nerve crush, subcutaneous application of GHRH agonist MR-409 or antagonist MIA-602 promoted the survival of RGCs. Both the GHRH agonist and antagonist increased the phosphorylation of Akt in the retina, but only agonist MR-409 promoted microglia activation in the retina. The antagonist MIA-602 reduced significantly the expression of inflammation-related genes Il1b, Il6, and Tnf Moreover, agonist MR-409 further enhanced the promotion of RGC survival by lens injury or zymosan-induced macrophage activation, whereas antagonist MIA-602 attenuated the enhancement in RGC survival. Our findings reveal the protective effect of agonistic analogs of GHRH on RGCs in rats after optic nerve injury and its additive effect to macrophage activation, indicating a therapeutic potential of GHRH agonists for the protection of RGCs against optic neuropathies especially in glaucoma.
Assuntos
Hormônio Liberador de Hormônio do Crescimento/agonistas , Macrófagos/patologia , Neuroproteção , Traumatismos do Nervo Óptico/patologia , Células Ganglionares da Retina/patologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Hormônio do Crescimento/metabolismo , Hormônio Liberador de Hormônio do Crescimento/antagonistas & inibidores , Inflamação/genética , Inflamação/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Microglia/efeitos dos fármacos , Microglia/metabolismo , Microglia/patologia , Neuroproteção/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Endogâmicos F344 , Receptores de Neuropeptídeos/metabolismo , Receptores de Hormônios Reguladores de Hormônio Hipofisário/metabolismo , Células Ganglionares da Retina/efeitos dos fármacos , Células Ganglionares da Retina/metabolismo , Fator de Transcrição STAT3/metabolismo , Sermorelina/análogos & derivados , Sermorelina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Corpo Vítreo/efeitos dos fármacos , Corpo Vítreo/metabolismo , Zimosan/farmacologiaRESUMO
Ocular inflammation is a major cause of visual impairment attributed to dysregulation of the immune system. Previously, we have shown that the receptor for growth-hormone-releasing hormone (GHRH-R) affects multiple inflammatory processes. To clarify the pathological roles of GHRH-R in acute ocular inflammation, we investigated the inflammatory cascades mediated by this receptor. In human ciliary epithelial cells, the NF-κB subunit p65 was phosphorylated in response to stimulation with lipopolysaccharide (LPS), resulting in transcriptional up-regulation of GHRH-R. Bioinformatics analysis and coimmunoprecipitation showed that GHRH-R had a direct interaction with JAK2. JAK2, but not JAK1, JAK3, and TYK2, was elevated in ciliary body and iris after treatment with LPS in a rat model of endotoxin-induced uveitis. This elevation augmented the phosphorylation of STAT3 and production of proinflammatory factors, including IL-6, IL-17A, COX2, and iNOS. In explants of iris and ciliary body, the GHRH-R antagonist, MIA-602, suppressed phosphorylation of STAT3 and attenuated expression of downstream proinflammatory factors after LPS treatment. A similar suppression of STAT3 phosphorylation was observed in human ciliary epithelial cells. In vivo studies showed that blocking of the GHRH-R/JAK2/STAT3 axis with the JAK inhibitor Ruxolitinib alleviated partially the LPS-induced acute ocular inflammation by reducing inflammatory cells and protein leakage in the aqueous humor and by repressing expression of STAT3 target genes in rat ciliary body and iris and in human ciliary epithelial cells. Our findings indicate a functional role of the GHRH-R/JAK2/STAT3-signaling axis in acute anterior uveitis and suggest a therapeutic strategy based on treatment with antagonists targeting this signaling pathway.
Assuntos
Células Epiteliais/patologia , Receptores de Neuropeptídeos/metabolismo , Receptores de Hormônios Reguladores de Hormônio Hipofisário/metabolismo , Transdução de Sinais/imunologia , Uveíte/patologia , Animais , Linhagem Celular , Corpo Ciliar/citologia , Modelos Animais de Doenças , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Humanos , Janus Quinase 2/metabolismo , Lipopolissacarídeos/imunologia , Masculino , Nitrilas , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Pirimidinas , Ratos , Receptores de Neuropeptídeos/antagonistas & inibidores , Receptores de Neuropeptídeos/imunologia , Receptores de Hormônios Reguladores de Hormônio Hipofisário/antagonistas & inibidores , Receptores de Hormônios Reguladores de Hormônio Hipofisário/imunologia , Fator de Transcrição STAT3/metabolismo , Sermorelina/análogos & derivados , Sermorelina/farmacologia , Sermorelina/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Uveíte/tratamento farmacológico , Uveíte/imunologiaRESUMO
PURPOSE: To determine the association of uric acid (UA) and glucose in aqueous humor with diabetic macular edema (DME) in patients with Type 2 diabetes. METHODS: Patients with DME or diabetes mellitus without retinopathy were enrolled from August 2016 to December 2020. Nondiabetic patients with age-related cataract or age-related macular degeneration were included as controls. RESULTS: A total of 585 eyes from 585 patients were included for this study. Statistical analysis showed that aqueous UA was associated with central retinal thickness (r = 0.39, P < 0.0001), with higher levels of UA in severe DME and lower levels in mild DME, suggesting an ocular source of UA from the diabetic retina. Aqueous UA {odds ratio (OR), 6.88 (95% confidence interval [CI], 2.61-18.12)}, but not aqueous glucose (0.95 [95% CI, 0.73-1.23]) or serum UA (0.90 [95% CI, 0.66-1.23]), was a stronger predictor for DME than the duration of DM (1.26 [95% CI, 1.12-1.42]) or hemoglobin A1c (1.35 [95% CI, 0.99-1.83]). If aqueous UA (<2.46 mg/dL) and aqueous glucose (<6.43 mmol/L) were used as reference, high UA (≥2.46 mg/dL) alone was associated with 5.83-fold increase in risk of DME, but high glucose (≥6.43 mg/dL) alone was not associated with DME. CONCLUSION: Increased aqueous UA, but not glucose, is an independent risk factor for DME. These data suggest that an intravitreal UA-lowering therapy could be beneficial for DME.
Assuntos
Diabetes Mellitus Tipo 2 , Retinopatia Diabética , Edema Macular , Humor Aquoso , Diabetes Mellitus Tipo 2/complicações , Retinopatia Diabética/complicações , Retinopatia Diabética/diagnóstico , Glucose , Humanos , Edema Macular/complicações , Edema Macular/etiologia , Fatores de Risco , Ácido ÚricoRESUMO
We previously found that epigallocatechin-3-gallate (EGCG) could inhibit the myofibroblast transformation of human Tenon's fibroblasts, however, the underlying mechanism remained unclear. We therefore investigated whether the autophagic regulation involved in the anti-fibrotic function of EGCG. The fibroblasts were subjected to transforming growth factor beta-1 (TGF-ß1) induction followed by EGCG treatments. The autophagic flux was examined by transmission electron microscopy and autophagic flux analysis. The levels of autophagy-related proteins (LC3ß and p62) and alpha-smooth muscle actin (α-SMA) were measured by Western blot and immunofluorescence. Results showed that TGF-ß1 partially inhibited the autophagic function of Tenon's fibroblasts. But this inhibition effect was rescued by LY2157299, a TGF-ßR1 selective inhibitor. Compared with the cells treated with TGF-ß1 alone, EGCG treatments increased the amount of autophagosomes and autolysosomes, evaluated the ratio of LC3-II to LC3-I and decreased p62 level. Our results indicated that EGCG could recover the activity of autophagy in the TGF-ß1-treated cells. Moreover, treatments with EGCG significantly decreased the α-SMA expression. Taken together, these findings revealed that autophagic regulation involved in the action of EGCG against TGF-ß1-induced transformation of Tenon's fibroblasts. Through increasing intracellular autophagy, EGCG could be a potential anti-fibrotic reagent for preventing subconjunctival fibrosis after glaucoma filtration surgery.
Assuntos
Antioxidantes/farmacologia , Autofagia/efeitos dos fármacos , Catequina/análogos & derivados , Miofibroblastos/efeitos dos fármacos , Cápsula de Tenon/efeitos dos fármacos , Fator de Crescimento Transformador beta1/farmacologia , Actinas/metabolismo , Adenoviridae/genética , Western Blotting , Catequina/farmacologia , Transdiferenciação Celular/efeitos dos fármacos , Células Cultivadas , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Proteínas Associadas aos Microtúbulos/metabolismo , Miofibroblastos/metabolismo , Miofibroblastos/ultraestrutura , Proteína Sequestossoma-1/metabolismo , Cápsula de Tenon/metabolismo , Cápsula de Tenon/ultraestrutura , Transfecção , Fator de Crescimento Transformador beta1/antagonistas & inibidoresRESUMO
Myofibroblast transformation of human Tenon's fibroblasts severely challenges the outcome of glaucoma filtration surgery. epigallocatechin-3-gallate (EGCG) is considered as a potential reagent to overcome this issue for its anti-fibrosis effect on various human diseases, but it is unclear on the fibrosis of Tenon's fibroblasts. This study was conducted to investigate the effect of EGCG on TGF-ß1-induced myofibroblast transformation of human Tenon's fibroblasts. The human Tenon's fibroblasts were incubated in the medium containing 10 ng/mL TGF-ß1, and subsequently treated with EGCG or mitomycin C (MMC). The cell proliferation and migration were analyzed. The expression of alpha-smooth muscle actin (α-SMA), type I collagen (Col-I), and p-Smad2/3 were also evaluated. It showed that EGCG and MMC strongly inhibited the elevation in cell number in tissue explants compared to the tissues treated with TGF-ß1 alone. Scratch-Wound assay showed that 48 h after TGF-ß1 induction, only 10% of the wound width remained. But cells treated with EGCG still showed over 93% wound width. Further, EGCG effectively inhibited TGF-ß1-induced expression of α-SMA and Col-I as well as phosphorylation of Smad2/3 in Tenon's fibroblasts. Altogether, we concluded that EGCG suppressed the myofibroblast transformation in Tenon's fibroblasts through inactivating TGF-ß1/Smad signaling. These findings demonstrate that EGCG can be considered as one of the possible antifibrotic reagents for preventing postoperative scarring in glaucoma filtration surgery.
Assuntos
Catequina/análogos & derivados , Glaucoma/tratamento farmacológico , Miofibroblastos/metabolismo , Cápsula de Tenon/metabolismo , Catequina/farmacologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Glaucoma/metabolismo , Glaucoma/patologia , Humanos , Miofibroblastos/efeitos dos fármacos , Miofibroblastos/patologia , Fármacos Neuroprotetores/farmacologia , Inibidores de Proteases , Transdução de Sinais , Cápsula de Tenon/efeitos dos fármacos , Cápsula de Tenon/patologiaRESUMO
IMPORTANCE: Age-related cataract is the leading cause of blindness worldwide. The pathological mechanisms causing this disease remain elusive. BACKGROUND: To examine the involvement of uric acid (UA) in the pathogenesis of posterior subcapsular cataract (PSC). DESIGN: Retrospective study and experimental investigation. PARTICIPANTS: A total of 180 patients with PSC or non-PSC were included. METHODS: Samples obtained from the patients were used to analyse content of UA and for histochemical examinations. The effects of UA on human lens epithelial cells were also investigated. MAIN OUTCOME MEASURES: Aqueous humour UA and urate deposits. RESULTS: The results showed a significant increase of aqueous humour UA in patients with PSC. After adjustment for potential confounders, elevated aqueous humour UA (odds ratio [OR] = 1.45) showed a stronger association with PSC than serum UA (OR = 1.10). Gomori methenamine silver staining revealed in PSC an intense deposit of urates in the lens fibres in equatorial regions, and in subcapsular fibres in posterior regions of the lens. Such staining was not detected in the lens with non-PSC. Treatment with UA-induced senescence and apoptosis in human lens epithelial cells in a dose dependent manner. Our results suggest that the elevated level of UA in aqueous humour causes a deposition of urates in human lens epithelium, which could possibly lead to dysfunction of these cells that generates opacification in PSC. CONCLUSIONS AND RELEVANCE: These findings indicate the local action of excessive UA in the pathogenesis of PSC. Control of serum UA level could delay the progression of PSC.
Assuntos
Catarata , Cristalino , Humor Aquoso , Humanos , Estudos Retrospectivos , Ácido ÚricoRESUMO
BACKGROUND: To report a case of femtosecond laser-assisted removal of an intracorneal chestnut. CASE PRESENTATION: A chestnut was obliquely protruding to the stroma of cornea and it was localized at the paracentral region on the left eye of a 32-year-old man. The best-corrected visual acuity (BCVA, in decimal values) was 0.6 in the injured eye. The white ulcers with feathery edges or satellite infiltrates were not observed in the lesion, and the anterior chamber was deep and quiet. Anterior segment optical coherence tomography (AS-OCT) demonstrated that the original entry path of the foreign body had been sealed, spanning a thickness of approximate 152 µm. In view of location of the intraocular chestnut at the paracentral region, femtosecond laser was applied according to the procedures of IntraLase Enabled Keratoplasty (IEK) to create an anterior lamellar flap rapidly and precisely. The lamellar flap was easily separated with a flap lifter, and the chestnut was removed entirely using a pair of forceps. In 3 days after surgery, the patient complained of mild pain and blurred vision. These symptoms were relieved after treatment with the eyedrops. At three-month follow-up, the corneal wound was healed well, and the BCVA was greatly improved to 1.2 in the left eye. A dot-like haze was observed corresponding to the scar at the site of foreign body removal. No surgical induction of corneal astigmatism was found in the corneal topography. CONCLUSIONS: Without induction of a visually significant scar and corneal astigmatism, the IEK procedure of femtosecond laser is of particular interest as it provides a unique method for removal of intracorneal foreign bodies impinging on the visual axis.
Assuntos
Doenças da Córnea/cirurgia , Transplante de Córnea/métodos , Corpos Estranhos no Olho/cirurgia , Lasers de Excimer/uso terapêutico , Nozes , Adulto , Humanos , Masculino , Resultado do TratamentoRESUMO
Disruptions in immunity and occurrence of inflammation cause many eye diseases. The growth hormone-releasing hormone-growth hormone-insulin-like growth factor-1 (GHRH-GH-IGF1) axis exerts regulatory effects on the immune system. Its involvement in ocular inflammation remains to be investigated. Here we studied this signaling in endotoxin-induced uveitis (EIU) generated by LPS. The increase in GHRH receptor (GHRH-R) protein levels was parallel to the increase in mRNA levels of pituitary-specific transcription factor-1, GHRH-R splice variant 1, GHRH, and GH following LPS insult. Elevation of GHRH-R and GH receptor was localized on the epithelium of the iris and ciliary body, and GHRH-R was confined to the infiltrating macrophages and leukocytes in aqueous humor but not to those in stroma. Treatment with GHRH-R antagonist decreased LPS-stimulated surges of GH and IGF1 in aqueous humor and alleviated inflammation by reducing the infiltration of macrophages and leukocytes and the production of TNF-α, IL-1ß, and monocyte chemotactic protein-1. Our results indicate that inflammation in the iris and ciliary body involves the activation of GHRH signaling, which affects the recruitment of immune cells and the production of proinflammatory mediators that contribute to EIU pathogenesis. Moreover, the results suggest that GHRH-R antagonists are potential therapeutic agents for the treatment of acute ocular inflammation.
Assuntos
Hormônio Liberador de Hormônio do Crescimento/uso terapêutico , Receptores de Neuropeptídeos/antagonistas & inibidores , Receptores de Hormônios Reguladores de Hormônio Hipofisário/antagonistas & inibidores , Sermorelina/análogos & derivados , Uveíte/prevenção & controle , Animais , Ensaio de Imunoadsorção Enzimática , Hormônio do Crescimento/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Ratos , Ratos Sprague-Dawley , Sermorelina/uso terapêuticoRESUMO
Excessive uric acid (UA) is associated with age-related cataract. A previous study showed that a high UA level in the aqueous humor stimulated the senescence of lens epithelial cells (LECs), leading to cataract progression. To better understand the underlying mechanisms, we investigated UA-driven senescence in human lens tissue samples obtained during surgery, rat lens organ cultures, and in vivo experiments, using senescence-associated ß-galactosidase (SA-ß-gal) staining, electronic microscopy, Western blotting, and histological analyses. Initially, we identified markedly higher expressions of NLRP3 and caspase-1 in the lens capsules of hyper-uricemic patients compared to normo-uricemic patients. This increase was accompanied by a significant rise in the SA-ß-gal positive rate. We next built a cataract model in which rat lenses in an organ culture system were treated with an increasing dosage of UA. Notably, opacification was apparent in the lenses treated with 800 µM of UA starting on the fifth day. Mechanistically, UA treatment not only significantly induced the expression of NLRP3, caspase-1, and IL-1ß, but also upregulated the levels of SA-ß-gal and the senescence regulators p53 and p21. These effects were fully reversed, and lens opacification was ameliorated by the addition of MCC950, a selective NLRP3 antagonist. Moreover, an in vivo model showed that intravitreal UA injection rapidly induced cataract phenotypes within 21 days, an effect significantly mitigated by co-injection with MCC950. Together, our findings suggest that targeting the UA-induced NLRP3 inflammasome with MCC950 could be a promising strategy for preventing cataract formation associated with inflammageing.
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PURPOSE: To compare ocular anatomy differences of lens subluxation between eyes with or without acute angle closure (AAC). METHODS: This is a retrospective and case-control study. Sixty cases with mild lens subluxation were recruited. Among them, 30 eyes with acute angle closure were assigned to the AAC group and 30 eyes without AAC were assigned to the non-AAC group. The anterior segment was quantitatively evaluated by ultrasound biomicroscopy (UBM). The axial length (AL) was measured with IOL Master. All patients underwent lens extraction surgery and were followed up for six months. RESULTS: The history of blunt trauma accounted for 22 (73.3%) cases in the AAC group and 21 (70%) cases in the non-AAC group. Fifteen (50%) patients in the AAC group had iridotomy history, and high intraocular pressure recurred. The UBM analysis showed that the average central chamber depth of the affected eyes in the AAC group was 1.82 mm, which was significantly shallower than that in the fellow eyes (2.58 mm, P < 0.05) or both eyes in the non-AAC group.Both eyes in the AAC group presented a shorter AL and shallower anterior chamber than the eyes in the non-AAC group. CONCLUSIONS: An asymmetrical anterior chamber between bilateral eyes is an important feature in lens subluxation-induced AAC. The crowded anterior chamber and shorter AL might be the anatomic basis for the eye with lens subluxation-induced AAC.
RESUMO
PURPOSE: To investigate the involvement of growth hormone-releasing hormone (GHRH) - growth hormone (GH) signaling in pathogenesis of proliferative diabetic retinopathy (PDR). DESIGN: Experimental laboratory study. METHODS: Vitreous humor, aqueous humor, and serum were obtained from 36 eyes of 36 patients with or without type 2 diabetes from 2017 to 2019. For histologic examination, 6 fibrovascular membranes were excised from eyes with active PDR. Three fibrovascular membranes were excised from nondiabetic patients with proliferative vitreoretinopathy (PVR) as controls. RESULTS: In PDR, the fibrovascular tissues consisted of a mature region containing fibrocytes, and an immature region populated by abundant polymorphonuclear leukocytes in a fibrinogen meshwork. Clusters of leukocytes were found adhering to the vascular walls. In PVR, no fibrinogen and polymorphonuclear leukocyte was observed in the fibrovascular membranes. The levels of GHRH and GH in PDR were significantly increased (P < .001), with 1.8-fold and 72.8-fold in vitreous humor, and 2-fold and 4.9-fold in aqueous humor, respectively, when compared with corresponding levels in controls. No significant difference was detected for insulin-like growth factor-1. Immunohistochemistry showed intense expression of GHRH and its receptor GHRH-R in polymorphonuclear leukocytes, vascular endothelial cells, and fibrocytes in fibrovascular membranes of PDR. GHRH staining was not detectable in infiltrating cells within the fibrovascular membrane of PVR. CONCLUSIONS: These findings reveal a possible involvement of GHRH/GHRH-R in fibrinous inflammation that might contribute to the formation of fibrovascular membrane in PDR through mediating activities of leukocytes, vascular endothelial cells, and fibrocytes. Targeting GHRH/GHRH-R may be considered as a potential therapeutic approach for the treatment of PDR.
Assuntos
Humor Aquoso/metabolismo , Retinopatia Diabética/sangue , Hormônio Liberador de Hormônio do Crescimento/sangue , Inflamação/sangue , Receptores de Neuropeptídeos/sangue , Receptores de Hormônios Reguladores de Hormônio Hipofisário/sangue , Corpo Vítreo/metabolismo , Adulto , Idoso , Diabetes Mellitus Tipo 2/metabolismo , Endotélio Vascular/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Fibroblastos/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Neutrófilos/metabolismoAssuntos
Angiofluoresceinografia , Edema Macular , Neuromielite Óptica , Complicações na Gravidez , Tomografia de Coerência Óptica , Humanos , Feminino , Neuromielite Óptica/diagnóstico , Neuromielite Óptica/complicações , Neuromielite Óptica/tratamento farmacológico , Gravidez , Edema Macular/diagnóstico , Edema Macular/tratamento farmacológico , Edema Macular/etiologia , Complicações na Gravidez/diagnóstico , Adulto , Angiofluoresceinografia/métodos , Acuidade Visual/fisiologia , Glucocorticoides/uso terapêutico , Imageamento por Ressonância MagnéticaRESUMO
Purpose: The aim of the study was to investigate the signaling of growth hormone-releasing hormone receptor (GHRH-R) in the pathogenesis of pterygium and determine the apoptotic effect of GHRH-R antagonist on pterygium epithelial cells (PECs). Methods: Fourteen samples of primary pterygium of grade T3 with size of corneal invasion ≥ 4 mm were obtained for investigation by histology, immunofluorescence, electron microscopy, explant culture, and flow cytometry. Results: We found that PECs were localized in the basal layer of the epithelium in advancing regions of the head of pterygium. These cells harbored clusters of rough endoplasmic reticulum, ribosomes, and mitochondria, which were consistent with their aggressive proliferation. Immunofluorescence studies and Western blots showed that GHRH-R and the downstream growth hormone receptor (GH-R) were intensively expressed in PECs. Their respective ligands, GHRH and GH, were also elevated in the pterygium tissues as compared to conjunctival cells. Explanted PECs were strongly immunoreactive to GHRH-R and exhibited differentiation and proliferation that led to lump formation. Treatment with GHRH-R antagonist MIA-602 induced apoptosis of PECs in a dose-dependent manner, which was accompanied by a downregulation of ERK1 and upregulation of Caspase 3 expression. Conclusions: Our results revealed that GHRH-R signaling is involved in survival and proliferation of PECs and suggest a potential therapeutic approach for GHRH-R antagonist in the treatment of pterygium.
Assuntos
Apoptose/efeitos dos fármacos , Pterígio/patologia , Receptores de Neuropeptídeos/antagonistas & inibidores , Receptores de Hormônios Reguladores de Hormônio Hipofisário/antagonistas & inibidores , Sermorelina/análogos & derivados , Western Blotting , Caspase 3/metabolismo , Contagem de Células , Proliferação de Células , Sobrevivência Celular , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Técnica Indireta de Fluorescência para Anticorpo , Hormônio do Crescimento/metabolismo , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Humanos , Microscopia Eletrônica de Transmissão , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Pterígio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Neuropeptídeos/metabolismo , Receptores de Hormônios Reguladores de Hormônio Hipofisário/metabolismo , Receptores da Somatotropina/metabolismo , Sermorelina/farmacologia , Transdução de SinaisRESUMO
Purpose. To compare the efficacy of subthreshold and conventional selective laser trabeculoplasty (SLT) in lowering intraocular pressure (IOP) in the patients with primary open-angle glaucoma (POAG). Methods. Fifty-two eyes from fifty-two POAG patients were randomized into two groups, one group treated with subthreshold SLT using two-thirds of the conventional energy and the other one treated with the conventional energy. IOP was measured with the Goldmann tonometer and the anterior chamber inflammation was determined using laser flare meter. Results. The initial energy dosage used in subthreshold SLT group was significantly lower than the amount of the energy used in conventional SLT group (0.4 ± 0.1 mJ versus 0.6 ± 0.1 mJ, P = 0.030). The total energy dosage was also significantly lower in subthreshold SLT group compared to the other group (37.6 ± 3.3 mJ versus 51.8 ± 5.7 mJ, P = 0.036). However, the level of inflammation in aqueous humor, amount of reduction in IOP, and the success rate in controlling IOP was the same in both groups. Conclusion. The efficacy of subthreshold SLT group in reducing IOP in POAG patients is comparable to the efficacy of conventional SLT group.
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Green tea extracts exhibit anti-oxidative and anti-inflammatory actions in different disease conditions. We hypothesized that green tea extract and its catechin constituents ameliorate sodium iodate-induced retinal degeneration in rats by counteracting oxidative stress. In this study, adult Sprague-Dawley rats were intravenously injected with a single dose of sodium iodate. Green tea extract (GTE; Theaphenon-E) or combinations of its catechin constituents, including (-)-epigallocatechin gallate (EGCG), were administered intra-gastrically before injection. Live imaging analysis using confocal scanning laser ophthalmoscopy and spectral-domain optical coherence tomography showed a progressive increase of degenerating profile across the retinal surface and decrease in thickness of outer nuclear layer (ONL) at Day-14 of post-injection. These lesions were significantly ameliorated by Theaphenon-E and catechin combinations with EGCG. Catechins with exclusion of EGCG did not show obvious protective effect. Histological analyses confirmed that Theaphenon-E and catechins containing EGCG protect the retina by reducing ONL disruption. Retinal protective effects were associated with reduced expression of superoxide dismutase, glutathione peroxidase and caspase-3, and suppression of 8-iso-Prostaglandin F2α generation in the retina. In summary, GTE and its catechin constituents are potent anti-oxidants that offer neuroprotection to the outer retinal degeneration after sodium iodate insult, among which EGCG is the most active constituent.
Assuntos
Catequina/farmacologia , Degeneração Retiniana/tratamento farmacológico , Chá/química , Administração Oral , Animais , Antioxidantes/farmacologia , Catequina/administração & dosagem , Catequina/análogos & derivados , Dinoprosta/análogos & derivados , Dinoprosta/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Iodatos/toxicidade , Oftalmoscopia/métodos , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , Degeneração Retiniana/induzido quimicamente , Degeneração Retiniana/patologia , Epitélio Pigmentado da Retina/efeitos dos fármacos , Epitélio Pigmentado da Retina/patologiaRESUMO
AIM: To investigate the role of microRNA-34a (miR-34a) in the induction of apoptosis of human lens epithelial (HLE-B3) cells. METHODS: The apoptosis of HLE-B3 cells was detected by Annexin V-PE apoptosis detection kit after the treatment with 200 µmol/L H2O2 for 24h and lentiviral miR-34a vector transfection. The expression of miR-34a in the cells was quantified by quantitative real time polymerase chain reaction (qRT-PCR) in response to H2O2 exposure and the vector transfection. The effects of overexpression of miR-34a on the expression of B-cell lymphoma-2 (Bcl-2) and silent information regulator 1 (SIRT1) was determined by qRT-PCR and Western blot. RESULTS: The expression of miR-34a was up-regulated by the treatment of H2O2 in HLE-B3 cells. The increased expression of miR-34a is accompanied with the cell apoptosis. Consistence with the H2O2 exposure, ectopic overexpression of miR-34a in HLE-B3 cells promoted cells apoptosis. Importantly the anti-apoptosis factors Bcl-2 and SIRT1 were reduced significantly by up-regulation of miR-34a in HLE-B3 cells. CONCLUSION: MiR-34a promotes the apoptosis of HLE-B3 cells by down-regulating Bcl-2 and SIRT1, suggesting that miR-34a may involve in the pathogenesis of cataract formation and targeting miR-34a may be a potentially therapeutic approach for treatment of cataract.
RESUMO
Green tea extract (GTE) exerts antioxidative activities in ocular tissues of rats, but high levels of (-)-epigallocatechin gallate (EGCG) can induce oxidative stress. In this study, pharmacokinetics, diurnal variation of oxidative status, antioxidation and transcription factors changes in ocular tissues of rats were investigated. Rats were fed intragastrically with GTE and catechin mixtures containing different amounts of EGCG. Plasma and various ocular tissues were taken for pharmacokinetic analysis, oxidation marker testings and gene expression assays. Effects of EGCG on ocular oxidation status were assessed by 8-isoprostane level and reduced/oxidized glutathione ratio. Oxidation, inflammation and apoptosis regulations in retina were evaluated by real-time polymerase chain reaction. Epicatechin, epigallocatechin and EGCG were dominant in various ocular tissues except vitreous humor, where gallocatechin was predominant. Diurnal variation of oxidative status was found in some compartments. GTE caused oxidative stress increase in the plasma, aqueous humor, vitreous humor, cornea and retina but decrease in the lens and choroid-sclera. Catechins mixture containing half dose of EGCG lowered 8-isoprostane in the retina and lens. GTE treatment induced superoxide dismutase 1 and glutathione peroxidase-3 expressions but suppressed catalase in the retina. Our results reveal pro-oxidation of GTE with high EGCG content to the ocular tissues. Optimal EGCG level is needed for protection.
Assuntos
Apoptose/genética , Catequina/análogos & derivados , Endoftalmite/genética , Chá/química , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Catequina/sangue , Catequina/farmacocinética , Catequina/farmacologia , Relação Dose-Resposta a Droga , Endoftalmite/dietoterapia , Olho/efeitos dos fármacos , Olho/fisiopatologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/química , Ratos Sprague-Dawley , Corpo Vítreo/efeitos dos fármacosRESUMO
Green tea extract (GTE) ingested by rats exerted anti-oxidative activities in various ocular tissues as shown in our previous studies. The present work investigated anti-inflammatory effects of GTE on endotoxin-induced uveitis (EIU). EIU was generated in adult rats by a footpad injection of 1 mg/kg lipopolysaccharide (LPS). Oral administration of GTE (550 mg/kg) was given one, two or four times after LPS injection. Twenty-four hours later, LPS produced severe hyperemia and edema in the iris. Immunocytochemical examinations showed an accumulation of infiltrating cells in the aqueous humor that were immunopositive for cluster of differentiation 43 (CD43) and CD68, markers for leucocytes and macrophages, respectively. Analyses of the aqueous humor showed an increase in pro-inflammatory mediators including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1). GTE treatments improved the clinical manifestations and reduced infiltrating cells and protein exudation in the aqueous humor, which were not observed under half dose of GTE (275 mg/kg). The number of CD68 positive macrophages residing in the iris and ciliary was also reduced. GTE suppressed production of TNF-α, IL-6 and MCP-1 in the aqueous humor, which was associated with a down-regulation of LPS receptor complex subunits, Toll-like receptor 4 (TLR-4) and CD14, and suppression of nuclear factor-kappa Bp65 (NF-κBp65) in the iris and ciliary body. Our findings show that GTE is a potent anti-inflammatory agent against the inflammation of EIU, and suggest a potential use in treatment of acute uveitis.
Assuntos
Extratos Vegetais/farmacologia , Chá , Uveíte/tratamento farmacológico , Animais , Humor Aquoso/citologia , Humor Aquoso/imunologia , Catequina/análogos & derivados , Catequina/farmacologia , Modelos Animais de Doenças , Endotoxinas , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Lipopolissacarídeos , Infiltração de Neutrófilos , Ratos , Ratos Sprague-Dawley , Chá/química , Uveíte/induzido quimicamenteRESUMO
Two MOF-74 analogs with OH groups on 1D channel surfaces have been synthesized through multi-component self-assembly at room temperature. Their guest-free forms demonstrate a potential luminescent probe or sensor for small molecules, and OH-MOF-74 (2a) also showed exceptional fluorescence quenching and enhancement behavior for different types of aromatic molecules.